Insulated extension clip-on test prod



NOV. 6, 1951 V. LANNOU 2,574,043

INSULATED EXTENSION CLIP-ON TEST PROD Filed Oct. 20, 1947 Inventor Victor Lannou WWW Patented Nov. 6, 1951 UNITED 4STATES PATENT OFFICE lINS'ULATED EXTENSION CLIP-0N i TEST PROD n Victor Laxman, Belly, Tex. v Application October 20, 1947, Serial No. 780,784

v2 Claims.

y ticularly in conjunction with electrical appurtenances.

An object of this invention is to perform tests upon radio tubes, electrical conductors, electrical equipment and the like.

Another object of this invention is kto provide means for attachment to a suitable terminal and provide means for selectively actuating said attachment means.

Another purpose of this invention is to -provide an insulating housing having electrically conductive jaws at one end thereof and means for conducting electrical current through said housmg.

Another purpose of this invention is to provide means for resiliently biasing the said jaws toward the closed or operative position.

Another purpose of this invention is to provide an extremely simple device of the nature to be described which is commercially feasible and which lends itself well to commercial manufacture.

Other purposes of the present invention lwill become apparent to those skilled in the art, in following the description of the preferred form of the invention, illustrated .in the accompanying drawing, wherein:

Figure 'l 'is a perspective view .of invention;

Figure 2 is a longitudinal sectional Yview of the invention shown in Figure 1 and taken on the line 2-'2 thereof and in the direction of the arrows;

Figure 3 is a transverse sectional view of the invention shown in Figure 2 kand taken on 'the line 3--3 thereof and 'in 'the direction of the arrows;

Figure 4 is a transverse view of the invention in Figure 2 and taken on the 'line 4--4 thereof and in the .direction of the arrows. n

Referring now in detail to theillustrated preferred form of the invention,likeireferencecharacters are used throughout to indicate similar elements.

This invention has been conceived and developed to provide a device for the purpose of testing various electrical apparatus both conveniently and easily. It often becomes necessary to test radio tubes, electrical appurtenances, electrical apparatus and the like. To this end the present invention has been developed including a pair of jaws which easily and conveniently clip upon the terminal or a selected portion of the device to be tested.

`the present Particularly embodied in the present inven. :tion is the `provision of improved means for actuating said jaws. In the embodiment illustrated in the drawing, a lockingdevice is yassociated with the means for actuating the jaws, which 'locking .device is -resiliently biased and engages one of a selected number of-teeth `of a rack gear inthe insulated housing.Y

The major portion of the `device vis composed of some suitable material such `as an insulating `plastic or the like. The jaws are electricallyrconductive as is the red. Current iiowing through the jaws. also flows through the said rod and then, `means is provided for conducting the -flowing current to an electrical outlet or plug which is secured at one end of the said housing. The Ymeans of conducting the current from the 'rod through the electrical plug will be described in detail 'asthe description proceeds.

Heretofore various types of test instruments of this nature `have been devised, however, utility of the present invention permits a person testin g instruments or other electrical apparatus to position the device on the terminal of the tested instrument andqlock the same in position while other necessary operations are performed. lThe most vcommon test means in -practical use involves only Aa length of wire or the like having an insulator thereon. This means requires the utility of both hands of the operator or at least one hand. The present inventionmay be clipped `and retained on the Vapparatus to be tested while other operations `may be performed by the operator of the invention.

. `Referring now to the vdrawing it Will be noted that an insulated housing .lil is provided with an aperture i2 longitudinally thereof. A slot I4 extends longitudinally of the said housing .lll

' and communicates with -the said yaperture l2.

A recess -IS is formed Iat v.one .end of the said housing Il) ,and provides Aas well .as forms means for receiving van electrical plug I3 therein. Of

- GQ11111562., this electrical plug has the usual insulated conductor 20 associated therewith. The wire `22 in said insulating conductor 2D extends through -a suitable bore 24 to a connecting element which is electrically conductive in nature and indicated at 26. A set screw is provided in a suitably threaded aperture in the said housing l0 and is engageable with the said wire Z2. Further note of this set screw will be made hereinafter.

A sleeve 3B is provided in said aperture l2 and has an annular ridge or detent 32 extending therearound. A rod 34 is slidably received in the said sleeve 30 and has a ared or bevelled slot 36 adjacent one end thereof.

Aligned slots 38 and 40 respectively are provided in the said sleeve 30 and a suitable pin 42 rides therein. This pin also extends through the said slot 36 and is preferably supplied with a suitable handle or actuating knob 44. Viewing Figure 3 it will be noted that the slot I4 is formed with an enlargement at the top portion thereof and serves the person as a recipient for the said handle 44.

A pin 4B extends through the said pin 42 and engages the lower surface of the said sleeve 30 adjacent the said slot 4G. A second pin 43 extends through the first mentioned pin 42 and is' substantially parallel to the said pin 46. The said pin 48 is also exterior of the said sleeve 3@ and has a spring 50 seated thereon. This spring also engages the inner surface of the said aperture l2 and by this constructionrit is quite obvious that the spring 50 normally vurges the pin 42 downwardly relative to the slot I4.

Arack gear 52 is provided at the lower surface .of the said aperture l2 and is engaged by the sharpened portion of the said pin 42.

It is now readily apparent that the rod 34 may gg be shifted to various positions and locked in position through the medium of the pin 42 and its resilient biasing spring 50. Means for resiliently biasing the said rod 34 to a select position is provided. This means is preferably a coil spring 54 ;l

teeth or gripping portions of the said jaws may be slightly curved for firm grip of various electrical contacts. These jaws have extensions 60 associated therewith which are received between/pairs of perches or brackets 62 and 64 respectively which are diametrically positioned on the said sleeve 30 and in a counter-bore formed at the end of the bore I2 in-the housing l0.V

Means for connecting the said jaws to the actuating rod 34 is provided. The preferable means consists of a pair of pitman rods 63 and 68 respectively connecting each of the said jaws to the said rod 34. Due to the nature of pitman rods, it is readily. appreciated that the terminal portions thereof may be connected to suitable pivot pins provided in the jaws and in the said rod 34.

Means for testing the test apparatus is provided. This means may be seen as the set screw 28 and the terminal portion of the said jaws. By simply placing a wire across the jaws and the set screw 28, after the test instrument has been energized, one may ascertain whether there is a complete electrical circuit from the jaws to the set screw` As is readily apparent from inspection of Figure 2, the sleeve is in electrical communication with the said receiving member 26.

There has been described and illustrated but one form of the invention. However, it is apparent that variations may be made without 4 departing from the spirit thereof. Accordingly, limitation is sought only in accordance with the scope of the following claims.

Having described the invention, what claimed as new is:

1. In an electrical circuit test apparatus, a housing having a lateral opening, a bore in said housing in communication with said lateral opening, a socket at one end of said housing adapted to retain a plug, a recess in the opposite end of said housing, `a pair of jaws mounted for pivotal movement in said recess, a rod slidably disposed in said bore, means pivotally connecting said jaws and said rod, electrically conductive means in said socket connected with said rod, and means for sliding said rod into selected positions comprising a handle slidably disposed in said lateral opening, a toothed rack formed in said housing within said bore, a pin fixed to said handle and slidably extended through a passage in said rod for engagement with the teeth of said rack, said pin :operatively connecting said handle to said rod, and a spring surrounding said pin and compressed between the housingV and pin to yieldingly engage said pin with the teeth of said rack,

2. In an electricalv circuit test apparatus, a housing having a lateral opening, a bore in said housing in communication with said lateral opening,.a socket at one end of said housing adapted to retain a plug, and a recess in the opposite end of said housing opening into said bore, a pair of jaws mounted for pivotal movement in said recess, a rod' slidably disposed in said bore, means pivotally connecting said jaws and said rod, electrically conductive means in said socket and connected-,\vith said rod, means slidably disposed in said lateral opening for sliding said rod, a pin on said last means slidably extending through a passage in said rod and operatively connecting said last means to said rod, a plurality of spaced teeth xed in said housing and disposed in said bore, said pin being engageable with said teeth selectively to retain said rod in selected positions, and a spring reacting on said pin and against said housing and yieldingly urging said pin into Vengagement with said teeth.

VICTOR LANNOU.

REFERENCES CITED The following references areof record in the le of this patent:

UNITED STATES PATENTS Number Name Date 760,273 Talbert May 17, 1904 919,971 Smith Apr. 27, 1909 1,621,745 Miller Mar. 22, 1927 1,869,181 Beck July 26, 1932 1,992,596 Bangel Feb. 26, 1935 12,067,995 Varner et al Jan. 19, 1937 2,208,023 Ellis July 16, 1940 2,222,110 Mauer Nov. 19, 1940 2,240,556 Eide May 6, 1941 2,457,506 .Sorensen v Dec, 28, 1948 

